Some Studies on NOX Reduction From a Diesel Engine Using Stabilized Emulsion

Abstract

The twentieth century has seen a rapid twenty-fold increase in the use of fossil fuels. Personal and commercial transportation consumes 2% of the total world energy. The main products of combustion of fossil fuel are carbon mono oxide (CO), unburned hydrocarbons (HC), Carbon dioxide (CO2), oxides of sulfur (SOx), oxides of nitrogen (NOx) and particulate matter. Oxides of nitrogen (NOx) are the major diesel engine pollutants and referred to as mixtures of nitric oxide (NO) and nitrogen dioxide (NO2). NOx emissions are required to be controlled because NO and NO2 contribute to the formation of smog, an environmental and human health hazard. NO2 is also directly of concern as a human lung aggravation. To reduce NOx emissions from a diesel engine, the introduction of water in the combustion chamber of a diesel engine is a promising option as vaporization of water reduces adiabatic flame temperature and micro-explosion phenomena lead to improved mixing. In the present study, stable D/W emulsion, with varying water content, up to 3% were prepared using span 80 as a surfactant. The results indicated a reduction in NOx and smoke with increasing water volume fraction in the emulsion compared to diesel baseline. However, beyond 2% water content led to increased ignition delay and higher diffusion phase heat release resulting in noisy engine operation. Therefore, it can be concluded that diesel-water emulsion with 2% water could be used for significant reduction of NOx emissions from diesel and biodiesel operation of a CI Engine.